Electro-chemical receiving-telephone



T. A. EDISON. Electro Chemical Receiving Telephone.

No. 23mm. paxemedm 3%, mm,

I UNITED STATES PATENT OFFICE.

THOMAS A. EDISON, OF llII XLO'lL-KRK, XIHV JERSEY.

ELECTRO-CHEMICAL RECEIVING-TELEPHONE SPECIFICATION forming part ofLetters Patent No 231,704, dated August 31, 1.880.

Application filed July '17 157i).

1'?) (all w/wm, it may concern: 1

Be. it known that I, THOMAS A. EDlSOX, ot' lilenlo Park, in the State ofNew Jersey, have invented a new and useful Improvement in i Telephones,of which the following is a specitication. (Case No. 181.)

The object of this invention is to transmit and reproduce overtelegraph-wires speech or other sounds telephonically.

The invention relates to an improved electro-cheuiicalreceiving-instrument and the method of working such receiving-instrumentby placing the same in a tertiary circuit and translating the electricwaves which serve to operate it by induction.

In the drawings, Figure 1 represents the apparatus andcircuit-connections at one end of the line, and Fig. 2 is asection ofthe call-hell battery. I Y

A is the transmitter, which consists of two buttons, 3 and 4, made offinely-divided conducting material, such as carbon, and facing f andresting at all times upon each other. :3 and .5 are metallic plateswhich are perina neatly-secured to these two buttons and serve toconnect the conducting-wires to the buttons. These are placed in arecessin an or dinary telephone-case, and a piece of rubber- T cloth,-1,Serves to keep the buttons in position and keep the moisture from them.

- The principle of operation is the same as in my previous applications,in which sound. waves are translated into electrical waves, the devicehere shown being mere] y a modification thereof.

"This transmitter is connected, in the circuit containing the batterySand key 9, with a cireuit-closing point, 10, and primary coil of theinductorium B. The key 9 serves to close the circuit in the act oftransmitting and to open of the cell there is laid a disk of carbon; on

it when receiving.

11 is the primary coil. coil, which is included in the main circuit by 1wires 50 and 51. I

The wire 50 proceeds to the earth E, while i 51 passes through thecall-bell magnet 25 to point 23, key-lever 22, and to the line. Henceany waves thrown into the secondary wire upon B pass to thewdistantstation.

v13 is the tertiary coil. In the circuit of the tertiary coil is theelectrochemical receiver 12 is the secondary 5 l withplatina orpalladium. experiment that when the arm is tipped with (l. The wire (it)passes to the arm 15 of the diaphragm 16, the end of which arm restsupon the moistened cylinder is.

The cylinder 18 is revolved continuously by means of a spring within thebarrel 19 giving motion to the train of gearing at 29. The

wire 61 returns to the other end of the tertiary coil.

20 is a battery which serves to keep a consta'nt current in tertiarycircuit.

The porous or chalk cylinder is kept moist by an electrolytic solution,such as water or l acidnlated water, and that part of the arm. 15

whielnr'ests upon the chalk is tipped eithcr l have found by palladiumthe battery 20 is not required in the circuit 61 to the tertiary coil13, but. when platinum is used the battery appears to be necessary toobtain the best results.

The operation of the electrochemical receiver is the same as in myapplication No. 175, except that the cylinder and arm are placed in atertiary circuit instead of being placed direct upon the line. Theobject of f placingitina tertiary circuit is to keep the apparatus freefrom earth-currents, which cause.

alterations in the volume of sound, owing to the marvelous delicacy ofthe apparatus.

The key .r serves to put the call-battery in circuit and disconnect thebell-magnet 25 andprimary12 from the circuit when callingv the distantstation.-

The battery 21 consists of a cell containing fifteen Mario Davybatteries, formed of disks of carbon and zinc fastened together byscrews, as in Fig. 2. After being .i'astened together they are boiled inparaiiine, and thcsurtace'ot' the zinc and carbonscraped. Fourteen ofthese doubledisks are used. At the bottom this is laid a layer ofsulphate of mercury paste; on this two sheets of moistened paper; onthis is laid a double disk with the zinc side down; on the carbon sideanother layer .of the mercurial saltzis laid, and the same order oflaying continued until the cell is finished. These are then sealed in aglass cell provided with a vent, into which water may be poured and beabsorbed by the paper.

I do not herein lay any claim to the trans niitting-instruincnt,nertothehatter [have and the'ci uit-e'unnectimix ut' the same. uil- 15shown these as adapted to the arrangement of stant'iully as set forth.t-ireuf '-e0nneeti0ns represented. 1 ii. In combination with a diaphragmand it 1 claim as my in\'enti0n 1 moving surface, an arm extending fromthe 1. 'lhceomhination,witlnt telephonictrunsdiaphragm to the movingSlllfttfl and tipped niitter, receiver, and line, ot'atertiaryinduefwith palladium,.t'orthe purpOScs andsuhstnn- 20 tioircoil. one coil ut'which is in the circuit to tinlly ns sct forth. the receiver, the otherin the circuit to the Signed by me this 17th day ut' July. l).transmitter, and the thirdinthe circuit to the l 1870. 10 linesubstantially as set forth. H

l. in cmnbinatiun with the transmittingand receiving inst rumcnts and atert izugr induction I \\'it ncsscs:

coil and circuits. substantially as set forth, a i h. L. (tnirrix,

cull undlm-nl lmtteryot'thechatrztetcrdcscrihed. i FRA .\'('|t lt.'l'r'rux'.

THUS. A. lilllhUX.

